Pale poo?...

Hi all my little 8 week old boy started being unwell yesterday 3am in the morning, he started having bad diarrhoea and had a mild fever. Wasn’t really interested in feeding and was unusually quiet. Ended up taking him to a&e on the night to be checked and doctor said she though it was just a stomach bug so he should be better after 48 hours.

He is still having the same poos today. They have a very strong fishy smell and are much paler then his normal poos.

What could it be??